U.S. patent application number 16/525553 was filed with the patent office on 2021-02-04 for inert gas system and method.
The applicant listed for this patent is Hamilton Sundstrand Corporation. Invention is credited to Haralambos Cordatos, Jonathan Rheaume.
Application Number | 20210031938 16/525553 |
Document ID | / |
Family ID | 1000004302866 |
Filed Date | 2021-02-04 |
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United States Patent
Application |
20210031938 |
Kind Code |
A1 |
Cordatos; Haralambos ; et
al. |
February 4, 2021 |
INERT GAS SYSTEM AND METHOD
Abstract
A system and method for providing inerting gas to a protected
space is disclosed. The system includes an air separation module
that includes an air inlet, a membrane with a permeability
differential between oxygen and nitrogen, a nitrogen-enriched air
outlet, and an oxygen-enriched air outlet. The system also includes
an air flow path between an air source and the air separation
module inlet, and an inerting gas flow path between the air
separation module nitrogen-enriched air outlet and the protected
space.
Inventors: |
Cordatos; Haralambos;
(Colchester, CT) ; Rheaume; Jonathan; (West
Hartford, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hamilton Sundstrand Corporation |
Charlotte |
NC |
US |
|
|
Family ID: |
1000004302866 |
Appl. No.: |
16/525553 |
Filed: |
July 29, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64D 37/32 20130101;
B01D 53/229 20130101; B01D 2256/10 20130101; B01D 2256/12 20130101;
A62C 3/08 20130101; B01D 53/228 20130101; B01D 2259/40083 20130101;
B01D 2253/1124 20130101 |
International
Class: |
B64D 37/32 20060101
B64D037/32; A62C 3/08 20060101 A62C003/08; B01D 53/22 20060101
B01D053/22 |
Claims
1. A system for providing inerting gas to a protected space,
comprising: an air separation module comprising an air inlet, a
membrane with a permeability differential between oxygen and
nitrogen, a nitrogen-enriched air outlet, and an oxygen-enriched
air outlet; an air flow path between an air source and the air
separation module inlet; an inerting gas flow path between the air
separation module nitrogen-enriched air outlet and the protected
space; and an adsorber configured to adsorb an acid precursor in
operative fluid communication with the air flow path.
2. The system of claim 1, wherein the air separation module
membrane comprises an organic polymer membrane.
3. The system of claim 2, wherein the polymer membrane comprises a
polyimide, polysulfone, or polycarbonate.
4. The system of claim 1, wherein the adsorber comprises a sorbent
selected from salts or oxides of alkaline metals, salts or oxides
of alkaline earth metals.
5. The system of claim 1, wherein the acid precursor comprises NOx
or SOx.
6. The system of claim 1, wherein the acid precursor comprises
NOx.
7. The system of claim 6, wherein the adsorber comprises catalyst
configured to oxidize nitrogen monoxide during sorption.
8. The system of claim 7, wherein the catalyst includes an
oxidation catalyst and a reforming catalyst.
9. The system of claim 1, further comprising a regenerative fluid
flow path in operative fluid communication between a fuel source
and the adsorber.
10. The system of claim 9, wherein the adsorber includes catalyst
configured to oxidize fuel, or catalyst to reform fuel, catalyst to
oxidize fuel and catalyst to reform fuel from the regenerative
fluid flow path during regeneration of the adsorber.
11. The system of claim 9, wherein the fuel source includes a fuel
tank that is also included in the protected space.
12. The system of claim 9, wherein the regenerative fluid flow path
includes a flow path from the air separation module
nitrogen-enriched air outlet, through the fuel source, to the
adsorber.
13. The system of claim 9, wherein the fuel source includes a fuel
vapor sorbent in operative fluid communication with a fuel
tank.
14. The system of claim 1, further comprising a controller
configured to operate the system in alternate modes of operation
including a first mode in which the acid precursor is accumulated
in a sorbent in the adsorber, and a second mode in which the
accumulated acid precursor is removed from the adsorber.
15. The system of claim 1, wherein the system is disposed on-board
an aircraft.
16. A method of producing inert gas, comprising directing air
through an adsorber configured to adsorb an acid precursor to
produce treated air; and directing the treated air through a
membrane with a permeability differential between oxygen and
nitrogen to produce inert gas comprising nitrogen-enriched air.
17. The method of claim 16, wherein the acid precursor includes
NOx, and the method further comprises oxidizing nitrogen monoxide
in the adsorber to facilitate adsorption.
18. The method of claim 17, further comprising regenerating the
adsorber by desorbing acid precursor from the adsorber.
19. The method of claim 18, further comprising directing a fuel to
the adsorber during regeneration, and optionally oxidizing the
fuel, or reforming the fuel, or oxidizing and reforming the fuel
during regeneration.
20. The method of claim 19, comprising removing fuel vapor from a
fuel tank vent line with a fuel sorbent, and directing fuel vapor
from the fuel sorbent to the adsorber during regeneration.
Description
BACKGROUND
[0001] The subject matter disclosed herein generally relates to
systems for generating and providing inert gas, oxygen, and/or
power such as may be used on vehicles (e.g., aircraft, military
vehicles, heavy machinery vehicles, sea craft, ships, submarines,
etc.) or stationary applications such as fuel storage
facilities.
[0002] It is recognized that fuel vapors within fuel tanks can
become combustible or explosive in the presence of oxygen. An
inerting system decreases the probability of combustion or
explosion of flammable materials in a fuel tank by maintaining a
chemically non-reactive or inerting gas, such as nitrogen-enriched
air, in the fuel tank vapor space, also known as ullage. Three
elements are required to initiate combustion or an explosion: an
ignition source (e.g., heat), fuel, and oxygen. The oxidation of
fuel may be prevented by reducing any one of these three elements.
If the presence of an ignition source cannot be prevented within a
fuel tank, then the tank may be made inert by: 1) reducing the
oxygen concentration, 2) reducing the fuel concentration of the
ullage to below the lower explosive limit (LEL), or 3) increasing
the fuel concentration to above the upper explosive limit (UEL).
Many systems reduce the risk of oxidation of fuel by reducing the
oxygen concentration by introducing an inerting gas such as
nitrogen-enriched air (NEA) (i.e., oxygen-depleted air or ODA) to
the ullage.
BRIEF DESCRIPTION
[0003] A system for providing inerting gas to a protected space is
disclosed. The system includes an air separation module that
includes an air inlet, a membrane with a permeability differential
between oxygen and nitrogen, a nitrogen-enriched air outlet, and an
oxygen-enriched air outlet. The system also includes an air flow
path between an air source and the air separation module inlet, and
an inerting gas flow path between the air separation module
nitrogen-enriched air outlet and the protected space. The system
further includes an adsorber configured to adsorb an acid precursor
in operative fluid communication with the air flow path.
[0004] Also disclosed is a method of producing inert gas. According
to the method, air is directed through an adsorber configured to
adsorb an acid precursor to produce treated air, and the treated
air is directed through a membrane with a permeability differential
between oxygen and nitrogen to produce inert gas comprising
nitrogen-enriched air.
[0005] In some aspects, the acid precursor can include NOx, and the
method can further include oxidizing nitrogen monoxide in the
adsorber to facilitate adsorption.
[0006] In any one or combination of the foregoing aspects, the
method can include regenerating the adsorber by desorbing acid
precursor from the adsorber.
[0007] In any one or combination of the foregoing aspects, the
method can include directing a fuel to the adsorber during
regeneration, and optionally oxidizing the fuel, or reforming the
fuel, or oxidizing and reforming the fuel during regeneration.
[0008] In any one or combination of the foregoing aspects, the
method can include removing fuel vapor from a fuel tank vent line
with a fuel sorbent, and directing fuel vapor from the fuel sorbent
to the adsorber during regeneration.
[0009] In any one or combination of the foregoing aspects, the air
separation module membrane can include an organic polymer
membrane.
[0010] In some aspects, the polymer membrane can comprise a
polyimide, polysulfone, or polycarbonate.
[0011] In any one or combination of the foregoing aspects, the
adsorber can comprise a sorbent selected from salts or oxides of
alkaline metals, salts or oxides of alkaline earth metals.
[0012] In any one or combination of the foregoing aspects, the acid
precursor can comprise NOx or SOx.
[0013] In any one or combination of the foregoing aspects, acid
precursor can comprise NOx.
[0014] In any one or combination of the foregoing aspects, the
adsorber can include catalyst configured to oxidize nitrogen
monoxide during sorption.
[0015] In any one or combination of the foregoing aspects, the
catalyst can include an oxidation catalyst and a reforming
catalyst.
[0016] In any one or combination of the foregoing aspects, the
system can further include a regenerative fluid flow path in
operative fluid communication between a fuel source and the
adsorber.
[0017] In any one or combination of the foregoing aspects, the
adsorber can include catalyst configured to oxidize fuel, or
catalyst to reform fuel, or catalyst to oxidize fuel and catalyst
to reform fuel from the regenerative fluid flow path during
regeneration of the adsorber.
[0018] In any one or combination of the foregoing aspects, the fuel
source can include a fuel tank that is also included in the
protected space.
[0019] In any one or combination of the foregoing aspects, the
regenerative fluid flow path can include a flow path from the air
separation module nitrogen-enriched air outlet, through the fuel
source, to the adsorber.
[0020] In any one or combination of the foregoing aspects, the fuel
source can include a fuel vapor sorbent in operative fluid
communication with a fuel tank.
[0021] In any one or combination of the foregoing aspects, the
system can further include a controller configured to operate the
system in alternate modes of operation including a first mode in
which the acid precursor is accumulated in a sorbent in the
adsorber, and a second mode in which the accumulated acid precursor
is removed from the adsorber.
[0022] In any one or combination of the foregoing aspects, the
system can be disposed on-board an aircraft.
[0023] In any one or combination of the foregoing aspects, the
system can further include a particulate filter and a catalytic
ozone treatment catalyst on the air flow path.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The following descriptions should not be considered limiting
in any way. With reference to the accompanying drawings, like
elements are numbered alike:
[0025] FIG. 1A is a schematic illustration of an aircraft that can
incorporate various embodiments of the present disclosure;
[0026] FIG. 1B is a schematic illustration of a bay section of the
aircraft of FIG. 1A;
[0027] FIG. 2 is a schematic illustration of an exemplary tubular
membrane for separating nitrogen and oxygen;
[0028] FIG. 3 is a schematic illustration of an example embodiment
of an inert gas generating system;
[0029] FIG. 4 is a schematic illustration of an example embodiment
of an inert gas generating system configured for regeneration of an
adsorber; and
[0030] FIG. 5 is a schematic illustration of another example
embodiment of an inert gas generating system configured for
regeneration of an adsorber.
DETAILED DESCRIPTION
[0031] A detailed description of one or more embodiments of the
disclosed apparatus and method are presented herein by way of
exemplification and not limitation with reference to the
Figures.
[0032] Although shown and described above and below with respect to
an aircraft, embodiments of the present disclosure are applicable
to on-board systems for any type of vehicle or for on-site
installation in fixed systems. For example, military vehicles,
heavy machinery vehicles, sea craft, ships, submarines, etc., may
benefit from implementation of embodiments of the present
disclosure. For example, aircraft and other vehicles having fire
suppression systems, emergency power systems, and other systems
that may utilize electrochemical systems as described herein may
include the redundant systems described herein. As such, the
present disclosure is not limited to application to aircraft, but
rather aircraft are illustrated and described as example and
explanatory embodiments for implementation of embodiments of the
present disclosure.
[0033] As shown in FIGS. 1A-1B, an aircraft includes an aircraft
body 101, which can include one or more bays 103 beneath a center
wing box. The bay 103 can contain and/or support one or more
components of the aircraft 101. For example, in some
configurations, the aircraft can include environmental control
systems (ECS) and/or on-board inerting gas generation systems
(OBIGGS) within the bay 103. As shown in FIG. 1B, the bay 103
includes bay doors 105 that enable installation and access to one
or more components (e.g., OBIGGS, ECS, etc.). During operation of
environmental control systems and/or fuel inerting systems of the
aircraft, air that is external to the aircraft can flow into one or
more ram air inlets 107. The outside air may then be directed to
various system components (e.g., environmental conditioning system
(ECS) heat exchangers) within the aircraft. Some air may be
exhausted through one or more ram air exhaust outlets 109.
[0034] Also shown in FIG. 1A, the aircraft includes one or more
engines 111. The engines 111 are typically mounted on the wings 112
of the aircraft and are connected to fuel tanks (not shown) in the
wings, but may be located at other locations depending on the
specific aircraft configuration. In some aircraft configurations,
air can be bled from the engines 111 and supplied to OBIGGS, ECS,
and/or other systems, as will be appreciated by those of skill in
the art.
[0035] With reference now to FIG. 2, the Figure schematically
depicts an exemplary membrane for separating nitrogen and oxygen.
FIG. 2 depicts a tubular membrane, but other configurations such as
planar membranes can also be used. As shown in FIG. 2, tubular
membrane 20 comprises a tubular shell 22. The membrane 20 can be
fabricated from a material that has selective permeability to
oxygen compared to nitrogen such that a pressure differential
across the membrane provided by a gas comprising nitrogen and
oxygen on the high-pressure side of the membrane will
preferentially diffuse oxygen molecules across the membrane. For
ease of illustration, the membrane 20 is depicted as a monolithic
hollow shell, and membranes fabricated solely out of the selective
oxygen-permeable membrane material are included within the scope of
this invention. However, in many cases, the membrane is a composite
of a substrate or layer that is permeable to both oxygen and
nitrogen and a substrate or layer that is selectively permeable to
oxygen.
[0036] The shell 22 defines a hollow core 26 that is open at both
ends. In use, pressurized gas comprising nitrogen and oxygen (e.g.,
air which is known to also contain trace amounts of noble/inert
gases) is delivered into the hollow core 26 at an inlet end 27 of
the membrane 20. The pressure of the air is greater than air
outside the core 26 such that a pressure differential between the
hollow core 26 and air at the exterior 24 of the membrane 20
exists. Oxygen molecules preferentially diffuse through the tubular
membrane 20 compared to nitrogen molecules, resulting in a flow of
OEA from the outer surface of the tubular membrane 20 as shown in
FIG. 2, and a flow of NEA from the hollow core 26 at the outlet end
28 of the membrane 20 as shown in FIG. 2. The membrane 20 can be
formed from different materials, including but not limited to
polymers (e.g., polyimides, polysulfones, polycarbonates) including
polymers of intrinsic microporosity ("PIM") (e.g.,
polybenzodioxanes) and thermally-rearranged ("TR") polymers (e.g.,
thermally-rearranged polybenzoxazoles), or refractory ceramics
(e.g., zeolite).
[0037] An example embodiment of an inert gas generating system 30
is schematically shown in FIG. 3. Fluid flows between the
components in FIG. 3 through the unnumbered arrowed lines that are
described contextually below unless explicitly identified and
numbered. As shown in FIG. 3, air from an air source 32 is directed
first to an optional filter module 34. The air source 32 can be any
type of air source including but not limited to a fan, blower, gas
turbine engine compressor bleed, a stand-alone compressor, ram air
inlet. The air source 32 can also be a simple inlet opening, with
motive force provided a blower, compressor, or similar device
disposed anywhere along the flow path. The optional filter module
34 can include one or more filter components, including but not
limited to a particulate filter (e.g., a HEPA filter) for removal
of particulates, or a coalescing filter for removal of liquid
entrained in the air flow. In the case of multiple filter
components, they can be integrated into a single module as shown in
FIG. 3 or can be disposed in separate modules (not shown) on the
air flow path. As further shown in FIG. 3, the air flow exiting
from the optional filter module 34 is directed to a catalyst module
36.
[0038] The catalyst module 36 includes the adsorber, and can also
include other air treatment components including but not limited to
an ozone treatment catalyst or particulate filter (e.g., a HEPA
filter). Alternatively, one or more such other air treatment
components can be disposed in separate modules (not shown) on the
air flow path. The adsorber can include an adsorbent washcoat and
catalyst disposed on a substrate. In some embodiments, the
substrate can be configured as a flow-through monolith having a
honeycomb structure with numerous parallel thin-walled channels
running axially through the substrate and extending between an
inlet and an outlet of the substrate. The channel cross-section of
the substrate can be any shape, but is preferably square,
sinusoidal, triangular, rectangular, hexagonal, trapezoidal,
circular, or oval. In some embodiments, the substrate can be
configured as a wall-flow monolith. In this configuration, axial
flow channels are alternately blocked, which allows the exhaust gas
stream to enter a channel from the inlet, then flow through the
channel walls, and exit the filter from a different channel leading
to the outlet, which can allow for particulates in the air flow
stream to be removed. In some embodiments, the substrate can be
formed from a refractory ceramic material, including but not
limited to alumina, silica, titania, ceria, zirconia, magnesia,
zeolites, silicon nitride, silicon carbide, zirconium silicates,
magnesium silicates, aluminosilicates, metalloaluminosilicates
(e.g., cordierite or spudomene), or a mixture or mixed oxide of any
two or more thereof. In some embodiments, the substrate can be
formed from a metal (including metal alloys or mixtures) capable of
withstanding heat resulting from operation, including but not
limited to titanium, stainless steel, ferritic alloys containing
iron, nickel, chromium, and/or aluminum in addition to other trace
metals.
[0039] The washcoat includes a slurry of particles comprising a
sorbent configured to adsorb an acid precursor, which can be
applied to the substrate by a coating process such as dip coating,
followed by drying and calcination. As used herein the term "acid
precursor" means any compound that can form an acid when exposed to
conditions or compounds that can form an acid such as a protic acid
or a Lewis acid. Examples of acid precursors include nitrogen
oxides (also known as "NOx") or sulfur oxides (also known as
"SOx"). The sorbent typically has a porous surface that provides
surface area for adsorption, and should be chemically compatible
with NOx for adsorption and retention. Example sorbents include but
are not limited to salts or oxides of alkali metals or alkaline
earth metals, zeolites. In some embodiments, the sorbent can
physically adsorb the acid precursor, and in some embodiments, the
sorbent can physiochemically adsorb acid precursors such as NOx or
SOx, such as according to the following example equations:
BaO+2NO.sub.2+1/2O.sub.2.fwdarw.Ba(NO.sub.3).sub.2 (1)
K.sub.2CO.sub.3+2NO.sub.2+1/2O.sub.2.fwdarw.2KNO.sub.3+CO.sub.2
(2)
2KNO.sub.3+SO.sub.2.fwdarw.K.sub.2SO.sub.4+2NO.sub.2 (3)
K.sub.2CO.sub.3+SO.sub.2+1/2O.sub.2.fwdarw.K.sub.2SO.sub.4+CO.sub.2
(4)
[0040] In some embodiments, the adsorber can include one or more
catalysts. The catalyst(s) can be applied to the sorbent before or
after washcoating by various techniques including but not limited
to impregnation, adsorption, or ion-exchange. In some embodiments,
the catalyst can include a catalyst for oxidation of nitrogen
monoxide to nitrogen dioxide that can be readily adsorbed by the
sorbent. Noble metals such as platinum, palladium, rhodium,
ruthenium, osmium, or iridium can be utilized to promote oxidation
of nitrogen monoxide, as well as other catalysts such as
multi-metal oxides, perovskites, carbon-based catalysts, cobalt, or
silver. In some embodiments, the catalyst can include catalyst to
promote a reforming reaction that forms a reducing environment to
promote removal of acid precursor from the sorbent. Many of the
above-mentioned noble metals catalysts can promote the reforming
reaction, and in some embodiments, a catalyst or catalyst
composition can be utilized. that is capable of performing both
functions. In some embodiments, however, the system can include
separate catalysts or catalyst compositions for the oxidation and
reforming functions. For example, a palladium catalyst can be
utilized to promote oxidation of nitrogen monoxide, and a rhodium
catalyst can be utilized to promote reforming of a fuel. For
embodiments in which separate catalysts or catalyst compositions
are utilized, the reforming catalyst can be integrated into the
adsorber upstream of the sorbent or can be in a separate catalyst
module disposed between a fuel source and the adsorber as described
below in further detail. Other catalytic functions can also be
performed.
[0041] The adsorber can be configured and operated as an active
adsorber or a passive adsorber. An active adsorber can be
regenerated by passing a reducing gas stream (e.g., a hydrogen-rich
gas stream such as can be formed by reforming a hydrocarbon fuel)
in operative fluid communication with the sorbent, whereas a
passive adsorber can be regenerated by passing a gas stream in
operative fluid communication with the sorbent without the need for
a reducing environment. With continuing reference to FIG. 3,
regeneration of the sorbent in the catalyst module 36 can be
carried out with a regeneration fluid stream delivered through flow
path 46 as described below.
[0042] During normal operation of the system, the adsorber operates
in an adsorption mode as acid precursor in the air flow from the
air source 32 is adsorbed by the sorbent in catalyst module 36, and
treated air exiting the adsorber is directed to an air separation
module (ASM) 38 (a bank of three ASM's is shown in FIG. 3). Oxygen
is preferentially transported through the membranes of the ASM 38
and nitrogen-enriched air (NEA) exits outlets from the ASM 38. The
NEA is directed to a protected space in the form of a fuel tank 42
(e.g., a center fuel tank of an aircraft) equipped with a vent
43.
[0043] As mentioned above, regeneration of the NOx sorbent can be
active or passive. In the passive mode, the fuel vapors can be
catalytically oxidized, using the same catalyst that promotes
oxidation of nitrogen monoxide or a different oxidation catalyst to
form a heated combustion gas for passive regeneration of the NOx
sorbent. In some aspects, regeneration can be carried out with
external regeneration components (e.g., as a maintenance operation)
or remotely (e.g., by swapping out the catalyst module 36 for a
fresh module. For example, an aircraft-based system adsorber may
only need to be operated during taxi operations where the aircraft
can be exposed to acid precursors in the exhaust of other aircraft,
and therefore may have sufficient capacity for that duration so
that it may not need regeneration during operation. In other
aspects, however, regeneration may be required during system
operation, in which case the system can include regeneration
components such as shown in FIG. 4 or FIG. 5. FIGS. 4 and 5 each
include a flow path 46 that directs fuel vapor from the fuel tank
42 to the catalyst module 36 for regeneration of the adsorber.
Regenerative flow of fuel vapor along the flow path of FIG. 4 can
be activated by operation of a valve or blower (not shown)
integrated with the flow path 46. In some aspects, an oxidation
catalyst for catalytic oxidation of the fuel can be disposed in the
catalyst module 36 or in a separate module (not shown) along the
flow path 46. For active regeneration, a reforming catalyst can
also be disposed in the catalyst module 36 or in a separate module
(not shown) along the flow path 46 to promote a reforming reaction
in which hydrocarbon fuel molecules undergo a reforming reaction in
which the hydrocarbon is converted to hydrogen and carbon dioxide.
The presence of hydrogen can provide a reducing environment that
promotes reduction of the stored acid precursors such as NOx stored
in the sorbent to form inert nitrogen. Some acid precursors may
require additional intervention to regenerate the adsorber. For
example, SOx accumulation in the adsorber may require desulfation
such as described in U.S. Pat. No. 7,036,489, the disclosure of
which is incorporated herein by reference in its entirety.
[0044] FIG. 5 schematically shows additional components for capture
of fuel vapor for use in regeneration of the adsorber. As shown in
FIG. 5, during a regeneration mode of operation, the valve 40 is
set to divert part or all of the NEA flow (which is typically at an
elevated temperature, e.g., about 185.degree. F.) to a fuel vapor
sorbent 44 that is shown disposed in a vent line in operative
communication with a vapor space of the fuel tank 42 to receive
fuel vapor therefrom. The fuel vapor sorbent 44 can include various
materials capable of storing fuel or fuel vapors therein, including
but not limited to activated carbon. Fuel vapor recovered from the
fuel vapor sorbent 44 is directed through the flow path 46 back to
the catalyst module 36 for regeneration of the NOx sorbent.
[0045] Acid precursors such as NOx and SOx can be present in the
environment, and the systems described herein can be operated in an
adsorption mode at any time for removal of acid precursors from air
bound for an air separation module. Acid precursors such as NOx
and/or SOx can also be formed from combustion of fuel, with NOx
resulting from oxidation of atmospheric nitrogen during combustion
and SOx resulting from oxidation of sulfur that may be present in a
fuel such as jet fuel or diesel fuel. Although bleed air that is
often used to supply the air separation module is drawn from a
compressor section of a gas turbine engine that is upstream of the
engine's combustor section, aircraft on the ground (e.g., at an
airport) can be exposed to engine exhaust from other aircraft,
which can contain NOx and/or SOx. Accordingly, in some embodiments,
the system employed on an aircraft can be operated in an adsorption
mode during aircraft operation on the ground, and can be operated
in a sorbent regeneration mode during flight or at a time when the
aircraft is on the ground other than during active aircraft
operation (e.g., during maintenance).
[0046] As further shown in FIGS. 3-5, the system 30 can include a
controller 48. The controller 48 can be in operative communication
with the catalyst module 36, the air separation module 38, the
valve 40, the fuel tank 42, the fuel vapor sorbent 44, and any
associated valves, pumps, compressors, conduits, pressure
regulators, or other fluid flow components, and with switches,
sensors, and other electrical system components, and any other
system components to operate the inerting gas system. These control
connections can be through wired electrical signal connections (not
shown) or through wireless connections. In some embodiments, the
controller 48 can be configured to operate the system according to
specified parameters, as discussed in greater detail further above.
The controller can be an independent controller dedicated to
controlling the inert gas generating system 30, or can interact
with other onboard system controllers or with a master controller.
In some embodiments, data provided by or to the controller 48 can
come directly from a master controller.
[0047] In some embodiments, the inert gas systems described herein
can provide a technical effect of promoting resistance to potential
degradation of the membranes used in air separation modules. Acid
precursors such as NOx and SOx can combine with water (e.g.,
ambient moisture) to form acids such as nitric acid or sulfuric
acid, which can in turn promote a hydrolysis reaction involving the
air separation module membrane that can degrade the structure of
the membrane. Additionally, in some embodiments, the absorption
(e.g., by fuel vapor sorbent 44) or other diversion of fuel vapors
for regeneration of the adsorber can provide a technical effect of
promoting reduction of fuel vapor emissions to the atmosphere.
[0048] The term "about" is intended to include the degree of error
associated with measurement of the particular quantity based upon
the equipment available at the time of filing the application.
[0049] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the present disclosure. As used herein, the singular forms "a",
"an", "the", or "any" are intended to include the plural forms as
well, unless the context clearly indicates otherwise. It will be
further understood that the terms "comprises" and/or "comprising,"
when used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, element components, and/or
groups thereof.
[0050] While the present disclosure has been described with
reference to an exemplary embodiment or embodiments, it will be
understood by those skilled in the art that various changes may be
made and equivalents may be substituted for elements thereof
without departing from the scope of the present disclosure. In
addition, many modifications may be made to adapt a particular
situation or material to the teachings of the present disclosure
without departing from the essential scope thereof. Therefore, it
is intended that the present disclosure not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this present disclosure, but that the present
disclosure will include all embodiments falling within the scope of
the claims.
* * * * *